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Flashcards in Exam 3 Deck (34):

What is the technique whereby a digital image is processed so that the columns and rows of the resulting product are aligned with north and east in a ground coordinate system?



Georeferencing is also sometimes called what?

Ground registration


What is the process of removing the effects of tilt from an aerial photograph?



What must happen first to compute the parameters of a two dimensional coordinate transformation which is the first step of Geo referencing an image?

A number of ground control points are selected which can be identified in the image and for which accurate ground coordinates are available


This first step in the process of georeferencing an image converts what?

It converts from ground coordinates x and y, to image coordinates X and Y.


Lowercase x and y are what type of coordinates?

Ground coordinates “from”


Uppercase X and Y are what type of coordinates?

Image coordinates “to”


What are the most often employed two dimensional coordinate transformations?

Conformal and affine


The process of Geo referencing an image involves two steps, step two is?

Filling an array, which is aligned with the ground coordinate system, with the appropriate digital numbers that quantify the brightness of the ground at the corresponding locations. This is known as resampling.


What’s the difference in the scan pattern of an oscillating mirror or rotating mirror?

An oscillating mirror has a zigzag pattern. A rotating mirror scans parallel lines


What are three kinds of lidar?

Airborne scanner terrestrial scanner bathymetric scanner


What are six applications of lidar?

Transmission line mapping, digital terrain model Contor maps cross-sections, water and sub water mapping, floodplain and drainage mapping, monitoring landfill volumes tree canopy and timber value, mobile street mapping


What is the word that means removing the effects of tilt in a photo?



What is the intent of vertical photography?

The camera axis is vertical and unavoidable aircraft tilts which cause the camera axis to be tilted are generally under 1° and seldom over 3°


What is exterior orientation?

It is the relationship between image and object space


What is the collinearity condition?

The model expresses that the image, lens, and object point lie on a straight line


What are the six parameters of exterior orientation that quantify the spatial position and angular orientation of a photograph?

Spatial position of the photo is defined by the 3-D coordinates of the exposure station in the ground coordinate system XL, YL, ZL  Angular orientation of the photo is defined by the three angles tilt, swing, azimuth or omega, Phi, kappa


In the auxiliary tilted photo coordinate system the Y prime axis coincides with what?

The principal line


In the auxiliary tilted photo coordinate system what is defined first?

Y prime And it coincides with the principal line


In the formula for the scale of a tilted photograph what is T and Y prime?

T is the tilt and Y prime is the coordinate of the point in the auxiliary system


In the auxiliary tilted photo coordinate system the letter N stands for what and the letter O stands for what?

N stands for nadir and O is the principal point on a tilted photo


Omega, Phi, and Kappa uniquely define the angular relationships between what?

Tilted coordinate system and the ground coordinate system


Omega is what?

Counterclockwise rotation about the X axis


Phi is what?

Counter clockwise rotation about the once rotated Y axis


Kappa is what?

Counterclockwise rotation about the twice rotated z-axis


In the Omega, Phi, Kappa system, capital XYZ is what and lowercase xyz is what?

Capital XYZ is ground coordinate system lowercase xyz is tilted photo image coordinate system


What does the letter L represent in the omega phi Kappa system?

L is the origin, the exposure station


What is rectification?

The process of creating equivalent vertical photographs from tilted photos


Space resection by collinearity?

Calculate six parameters of exterior orientation, three angular attitude and three camera position of a photograph


Resampling essentially re-samples amounts to determine what?

The DN value for a fractional row and column location


What re-sampling method is the fastest?

Nearest neighbor


How many surrounding pixels are used in bilinear Interpolation?

4 surrounding pixels


How many surrounding pixels are used in bicubic interpolation?

16 surrounding pixels


What is the most common viewing system for stereo scopic plotting?

Alternating LCD shutter display